Only two beacon deployments were made during the leg, and both were successfully released and recovered. Using GPS, we deployed an initial beacon (S.N. 2040, 205 dB, 14.0 kHz) at the original SatNav coordinates for the hole reported by Leg 118. Positioning on this beacon, we conducted an expanding box search pattern until the guide base was located. We then dropped a second beacon (S.N. 2025, 208 dB, 16.0 KHz), which was used as the primary positioning beacon for the remainder of the leg. The primary beacon rested ~13 m from the HRB, and the back-up beacon was ~60 m away. Both beacons were deployed ~38 days, and we experienced no problems with either one.

The special tilt beacons sent out for use with the HRB were diagnosed with several problems. The Sedco Electronic Technicians (ETs) made several modifications to S.N. 1040, and it now functions correctly. It was left aboard for possible use on Leg 179. Since we did not have to set a new HRB, we never had occasion to deploy any tilt beacons during Leg 176. The second beacon, S.N. 1039, would only operate at 195 dB. All other output power settings caused the battery fuse to blow. The third beacon, S.N. 1137, would not be recognized by the ship's RS/906 receiver. Both of the later beacons were returned to shore for repair by Datasonics.

The ASK system functioned well throughout the leg. During one force 8/9 gale, there were several yellow and red positioning alarms, but we anticipated this because of the very small operating window resulting from the shallow (731 m) water depth. For normal (deep water) operations the alarms are set at 2% and 3%, respectively. For Leg 176, because of the shallow water, the alarms were set at 3% (22 m) and 5% (37 m). Additional details are included in the body of this report.

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